TW202228527A - Edible cultured eel - Google Patents

Abstract

To provide an edible cultured eel with high quality that has a high lipid content in the skeletal muscles. An edible cultured eel with high quality that has a high lipid content in the skeletal muscles, a group of edible cultured eels including such eel individuals, etc. The present invention includes an edible cultured eel, etc., said edible cultured eel satisfying formula I [wherein: X stands for the body weight (g) of the eel; and Z stands for the lipid/protein ratio] depending on the lipid content in the skeletal muscles of the eel. Even after growing up, the flesh of such eels is not toughened but high-level flesh tenderness and good quality and taste are maintained. (I): Z > -0.001X+1.95 (250 < X < 1,800).

Description

Edible farmed eel

The present invention relates to a high-quality edible cultured eel with a relatively high lipid content in skeletal muscle, a group of edible cultured eel containing the individual eel, and the like.

Eel is the general name of the fish of the genus Eel, and there are 19 species of Japanese eels, sea eels, and European eels known in the world. Eel has been eaten by humans in Europe and East Asia since ancient times, and it is a traditional and popular ingredient especially in Japan.

For example, the Japanese eel (scientific name "Anguilla japonica"), which grows in the whole of East Asia including Japan, is generally considered to lay eggs near the Mariana Islands in the Pacific Ocean. Young eels of about ~0.3g reach coastal waters in East Asia along the Kuroshio current. Then, it settles in inland waters, coastal waters, steam waters, and other waters and grows into small eels (spots, etc.), and it takes five to ten years to mature, and migrates toward the spawning place again. Although other eels have different spawning places and settlements, their life forms are almost the same.

Farmed eels are popular due to high demand and high profits. It is generally believed that more than 99% of the total consumption is farmed eels. The current mainstream eel farming method is to use the natural juvenile eels that swim to the coastal waters as seedlings for aquaculture, release them to aquaculture ponds, and raise them. In addition, regarding the complete culture of the juveniles obtained by artificial hatching to grow into adult eels and further obtain the next generation of juveniles, although there have been successful reports in the experimental stage, it has not yet reached the stage of commercial mass production.

Generally speaking, male eels grow slowly when they weigh more than 300g, but the meat becomes hard, resulting in poor quality and taste. On the other hand, the growth limit of female eels is greater than that of male eels. Even if they weigh more than 300g, they will not be dulled, and they can keep the meat soft and tender when they grow, and also keep the quality and taste unchanged. However, if young eels are raised in an aquaculture environment, almost all of them will become male eels, so it is difficult to obtain female eels. Therefore, edible cultured eels are cultivated and shipped on the premise of male eels. That is, if the meat grows too hard, the quality and taste will be deteriorated, and the commercial value will be lost. Therefore, the edible cultured eel is usually shipped before the weight reaches 250g.

In addition, it is known that feminization can be induced by adding a female hormone (estradiol 17β) to a mixed feed and feeding a bait during the period of growth from a young eel to a young eel. In addition, as a means for feminizing eels without using hormones, for example, Patent Document 1 describes a method in which a hollow housing member is arranged in a water tank, and the housing member can cover the whole body of the eel that has entered the inside, and before the breeding performance is differentiated in the water tank of eels, thereby promoting feminization.

Next, soy isoflavones, which are matters related to the present invention, will be described.

Soy isoflavones are a general term for flavonoid-based compounds with isoflavones as the basic skeleton, which are mainly present in soybean germs and the like. Soy isoflavones can be classified into glycosides (glycosides; structures covalently bonded to sugar groups), aglycones (non-glycosides; structures after the glycosyl moieties of glycosides are removed), acetosides of glycosides, and glycosides There are a total of 4 kinds of malonyl compounds. There are 3 known compounds in each classification, and a total of 12 known compounds of soybean isoflavones. Among them, the three soybean isoflavones of the glycoside type are genistin, daidzin, and glycitin. Isoflavones (genistein), soybean isoflavone glycosides (daidzein), glycitein (glycitein). The composition and content of each compound vary depending on the type of raw soybeans, etc., extraction, purification, processing methods, and the like. Moreover, as a means for isolating specific compounds in soybean isoflavones, for example, Patent Document 2 discloses means for isolating high-purity genistein from an isoflavone mixture using a solvent.

Soy isoflavones are chemically similar to the female hormone (estrogen), also known as phytoestrogens. In addition, aglycone-type soybean isoflavones have functions such as estrogen, and are generally considered to be effective in preventing heart disease, menopausal disorders, osteoporosis, breast cancer, and the like.

In addition, Non-Patent Document 1 discloses that 55% of European eels were fed with genistein at 2 mg/kg (dry food) daily for 100 days, and 55% of them became females. kg (dry) of genistein, only 15% became females. [Prior Art Literature] [Patent Literature] Patent Document 1: Japanese Patent Laid-Open No. 2018-143182. Patent Document 2: Japanese Patent Application Laid-Open No. 7-173148. [Non-patent literature] Non-patent document 1: Itai Tzchori, et al, “The influence of phytoestrogens and oestradiol-17β on growth and sex determination in the European eel (Anguilla Anguilla)”, Aquaculture Research, 2004, 35, 1213-1219.

[The problem to be solved by the invention]

As mentioned above, almost all eels will become male eels if they are raised in a breeding environment from juveniles to young eels. It is difficult for male eels to grow to a medium size or above, or they grow but the meat becomes hard and the quality and taste deteriorate. Therefore, compared with natural eels that have been grown in the natural environment, they are caught and eaten by humans, especially when compared to such natural eels. For female eels, most of the edible cultured eels in the market are small eels weighing 200 to 250 g. In addition, the lipid content in the skeletal muscle of the medium-sized and above cultured eels is not high, which leads to poor quality and taste.

On the other hand, a simple, safe and stable technology for producing female eels in aquaculture environment has not been established at present. Therefore, at present, edible cultured eels of medium and large size with high lipid content in skeletal muscle and better quality and taste have not yet been established. mass-produced and supplied to the market.

Therefore, an object of the present invention is to provide a high-quality edible cultured eel having a medium size or larger and a high lipid content in skeletal muscle. [means to solve the problem]

The inventors of the present invention succeeded in easily and stably producing female eels in a culture environment by adding soy isoflavones to bait for eels in the juvenile/young eel period. Therefore, for the first time, the production and mass production of high-quality edible cultured eel with a medium size and above and a high lipid content in skeletal muscle has been realized.

Therefore, the present invention provides a high-quality edible cultured eel having a medium size or above and a high lipid content in skeletal muscle, a group of edible cultured eel containing the individual eel, and the like.

According to the lipid content in eel skeletal muscle, the present invention includes an edible cultured eel, where the eel body weight is X (g) and the lipid/protein ratio is Z, the following formula (I) is satisfied. Z>-0.001X+1.95 (250<X<1,800) (I).

Furthermore, it includes an edible cultured eel whose body weight exceeds 250 g, the value of the following formula (A) is BMI, and when the BMI value is Y and the lipid/protein ratio is Z, the following formula (II) is satisfied. BMI=weight (g)/{full length (mm)} ² (A). Z>-Y+2.45 (0.2<Y<2.0) (II).

In addition, an edible cultured eel, whose body weight exceeds 250 g, satisfies the following formula (III) when the gonad weight per unit body weight is a (%) and the breaking load of the fish meat when thermally processed for 10 minutes is b (N). b<2a+1 (0.1<a<4) (III).

In aquaculture, during the specific period of the growth period from juvenile eel to young eel, for example, during the period of indeterminate sex or gender plasticity, ingestion of eel feed supplemented with soybean isoflavones, etc., can be simple and high in the breeding environment. Efficient and stable production of female eels. Thereby, production and mass production of high-quality edible cultured eel having a medium size or larger and a high adipose tissue ratio in skeletal muscle can be performed.

In addition, in the present invention, "small eel" refers to a juvenile eel that grows more than a juvenile eel. Hereinafter, for the sake of convenience, those with a body weight of less than 0.5 g are referred to as juvenile eels, and those with a body weight of 0.5 g or more are referred to as young eels. [Effect of invention]

According to the present invention, high-quality edible cultured eel and the like with a relatively high lipid content in skeletal muscle can be provided.

<The edible cultured eel of the present invention> The present invention broadly includes high-quality edible cultured eels with a medium size and above and a relatively high lipid content in skeletal muscle.

The size of the edible cultured eel of the present invention is medium or larger, specifically, the body weight is preferably more than 250g, more preferably more than 300g, and most preferably more than 350g. Moreover, the weight of the eel is preferably less than 1,800 g, more preferably less than 1,500 g, and most preferably less than 1,200 g.

In addition, the edible cultured eel of the present invention broadly includes those whose body weight is within the above-mentioned range and the lipid content in skeletal muscle is relatively high, that is, after the body weight, for example, grows over 250 g, the meat quality will not become hard and can maintain tenderness, quality, good taster.

In the present invention, it was newly discovered that there is a specific correlation between the eel body weight and the lipid/protein ratio in accordance with the lipid content level in the eel skeletal muscle. Based on this finding, the present invention includes an edible cultured eel that satisfies the following formula (I)' when the eel body weight is X (g) and the lipid/protein ratio is Z. Z>-0.001X+1.95 (I)'.

In the formula (I)', the range of the weight X of the eel is as described above.

In the formula (I)', the lipid/protein ratio Y can be obtained by a known nutrient analysis method or the like. For example, skeletal muscles such as the back and abdomen of an eel can be extracted, and the amount of protein and the amount of lipid can be measured by known nutrient analysis, and the lipid/protein ratio can be calculated.

Furthermore, in the present invention, it was newly discovered that there is a specific correlation between the BMI (body mass index) value of eel and the lipid/protein ratio in accordance with the lipid content in the skeletal muscle of eel. According to this finding, the present invention includes an edible cultured eel, the value of the following formula (A) is BMI, and when the BMI value is Y and the lipid/protein ratio is Z, the following formula (II') is satisfied. BMI=weight (g)/{full length (mm)} ² (A). Z>-Y+2.45 (II').

In the formula (II'), the BMI value Y is preferably more than 0.2, more preferably more than 0.5, and most preferably more than 0.8. Moreover, the BMI value Y is preferably less than 2.0, more preferably less than 1.8. The lipid/protein ratio is the same as above.

Moreover, in the present invention, it was newly discovered that there is a specific relationship with the breaking load of fish meat during thermal processing in accordance with the lipid content in eel skeletal muscle. Based on this finding, the present invention includes an edible cultured eel that satisfies the following formula (III') when the gonad weight per unit body weight is a (%), and the breaking load of the fish meat when thermally processed for 10 minutes is b (N). b<2a+1 (III’).

The gonad weight per unit body weight, that is, the gonad weight index a (%) can be calculated by a known method, for example, by removing gonads from individual eels and measuring their weight, dividing by the body weight and multiplying by 100. In formula (III'), the gonad weight index a is preferably more than 0.1%, more preferably more than 0.35%. Further, the gonad weight index a is preferably less than 4%, more preferably less than 3%, and most preferably less than 2%.

The breaking load b(N) of the fish meat at the time of heat processing for 10 minutes is obtained as an index of the hardness of the fish meat after heat conditioning, and can be measured by a known method. For example, one side of eel is cooked at a cumulative temperature of 510,000[°C･sec] and both sides are cooked. Conditioning on one side can be performed, for example, at 600 to 1,000° C. for 510 to 850 seconds. The conditioning machine is preferably an electric heating pan. After the heating conditioning, the rupture load b is measured with an elasticity measuring device such as a rheometer or the like with respect to a specific part of the body (abdomen, etc.) after the heating conditioning.

In addition, in the edible cultured eel of medium size and large size with a high degree of lipid content in the skeletal muscle, the adipose tissue in the skeletal muscle of the back or abdomen is in a state where the network is locally present.

Here, "a state in which the adipose tissue is locally present in the form of a mesh" means that the adipose tissue is deposited in an irregular mesh shape in the entire muscle, and the deposition ratio is higher than that of a standard eel and the adipose tissue is fine. Although they are different foods, they are equivalent to grades 4 and 5 of the beef carcass trading standard of the Japan Meat Grading Association. The eel, which is the object of the present invention, has obvious body side muscles, and it can be considered that the eels whose body side muscles have a fat tissue area ratio (adipose tissue area/total cross-sectional area) of 35% or more are eligible. Generally, the area of adipose tissue in the muscles of the ventral body is higher than that of the dorsal side, which can be more than 37% in the muscles of the ventral body.

In addition, the species of eel to be targeted by the present invention is not particularly limited as long as it belongs to the genus Eel of the family Anelidae. For example, Japanese eel (scientific name "Anguilla japonica"), sea eel (scientific name "Anguilla marmorata"), European eel (scientific name "Anguilla anguilla"), American eel (scientific name "Anguilla rostrata") and the like. In the present invention, the aforementioned eel is preferably Japanese eel.

<The edible cultured eel group of the present invention> As mentioned above, almost all of them become male eels in the breeding environment, and there are no individuals on the market that are medium-sized or larger and have a high lipid content in skeletal muscle, accounting for more than a certain proportion of individuals. That is, the present invention can provide the edible cultured eel for the first time to the market, and the present invention includes a group formed by a plurality of the above-mentioned edible cultured eel individuals.

Considering that the production rate of female eels in the breeding environment is almost 0%, and the production rate of female eels that have not been produced in the past, for example, more than 10, is a group of edible cultured eels containing the above-mentioned edible cultured eel individuals at a ratio of 12% or more, more preferably 15% or more. The swarm of edible cultured eel contained in a proportion of 25% or more is preferably the swarm of edible cultured eel contained in the proportion of more than 25%, so the present invention includes the swarm of edible cultured eel of the present invention.

<The production method of edible cultured eel, etc. of the present invention> The production method of the edible cultured eel or the like of the present invention is not particularly limited. For example, these edible cultured eels and their flocks can be produced and mass-produced by ingesting the eel feed or eel-inducing feminizing agent described later in the stage of young eels and/or young eels. In addition, the present invention is not limited to those produced and mass-produced by the methods shown below.

Eels will undergo sex differentiation in a specific period from the growth of young eels to small eels (for example, during the growth period until the body weight reaches 0.2g~30g). to distinguish between males and females. Then, by ingesting these eel feeds or eel-inducing feminizing agents, for example, during the juvenile and/or young eel period before and after the sex differentiation period, eel feminization can be induced reliably and efficiently, and the Production and mass production of high-quality edible aquaculture eels (groups) of medium size and above with high lipid content in skeletal muscle.

The means for ingesting the eel feed or the eel feminizing agent is not particularly limited. For example, it can be carried out by feeding these bait, it can also be ingested separately, and these can also be administered directly to an individual eel.

The period of ingestion of the eel feed, the eel feminization-inducing agent, etc. is not particularly limited as long as it includes the period of sex differentiation and the period before and after it. For example, there is a high possibility that the feminization of eels can be reliably and efficiently induced by continuously ingesting these feeds or feminizing agents for 2 to 6 months in the period of juveniles and/or young eels.

The frequency of ingesting the eel feed, the eel feminizing agent, etc. is not particularly limited as long as the ingestion is continued without interruption during the period of ingestion or the like. For example, by ingesting these feeds or feminization-inducing agents on 3 to 7 days a week, there is a high possibility that eel feminization can be induced reliably and efficiently. In addition, depending on the degree of growth of the eel, for example, the daily intake can be further divided into 2 to 3 times during the period from the baby eel to the baby eel (for example, the body weight is 0.2 g to 20 g), and the daily intake can be further divided into 2 to 3 times. The daily intake is given at one time.

＜Feed for eel＞ In the production of edible cultured eel (or a group thereof) according to the present invention, the feed for eel can be, for example, one containing 0.05% by weight or more of soybean isoflavone in a dry matter ratio, or one containing 0.05% by weight or more of soybean isoflavone aglycone in a dry matter ratio. , and those containing more than 0.006% by weight of genistein in a dry matter ratio.

Contains soy isoflavones (or soy isoflavone aglycone, or one or two or more of these specific compounds, such as genistein, etc.) in eel feeds, and is used for a fixed period of time in juveniles and/or young eels By feeding the feed, eels can be induced to feminize, thereby enabling the production and mass production of high-quality edible cultured eels with a medium-sized or larger size and a high ratio of adipose tissue in skeletal muscle.

Water, feed oil (fish oil), etc. are often added to mixed feeds as feeds for eels, kneaded into a paste, and then fed to eels.

In the feed for eel, the ratio of dry matter (dry material, the same below), that is, when the weight of the feed before preparation (adding water, etc.) at the time of use, is 100%, soy isoflavones preferably contain 0.05% by weight or more, more preferably It is 0.2 weight% or more, Preferably it is 1.0 weight% or more. The upper limit of the soybean isoflavone content is not particularly limited, but from the viewpoint of feed efficiency, it is preferably 20% by weight or less, more preferably 8.0% by weight or less, and most preferably 4.0% by weight or less.

A known soy isoflavone can be used, and is not particularly limited. For example, a finished product may also be used, or one extracted, purified, processed and prepared from soybeans as a raw material by a known method may be used.

In other respects, in the feed for eel, the dry matter ratio, that is, when the weight of the feed before preparation (adding water, etc.) at the time of use, is 100%, the soybean isoflavone aglycone preferably contains 0.05% by weight or more, more It is preferably 0.2% by weight or more, and most preferably 1.0% by weight or more. The upper limit of the content ratio of soybean isoflavone aglycone is not particularly limited, but from the viewpoint of feed efficiency and the like, it is preferably 20% by weight or less, more preferably 8.0% by weight or less, and most preferably 4.0% by weight or less. In addition, "soy isoflavone aglycone" is the non-sugar moiety in soy isoflavones (the same applies hereinafter), and its content can be obtained, for example, by converting the weight of added soy isoflavones to the molecular weight ratio of glycoside and aglycone, Moreover, it can be analyzed by a well-known test method.

From another aspect, in the feed for eel, the dry matter ratio, that is, when the weight of the feed before preparation (adding water, etc.) during use, is 100%, genistein preferably contains 0.006% by weight or more, more It is preferably 0.02% by weight or more, and most preferably 0.1% by weight or more. The upper limit of the content ratio of genistein is not particularly limited, but from the viewpoint of feed efficiency and the like, it is preferably 5.0% by weight or less, more preferably 2.0% by weight or less, and most preferably 1.0% by weight or less.

The means of adding genistein to the eel feed is not particularly limited. For example, genistein can be added to the eel feed by adding soybean isoflavones containing genistein to the eel feed, or directly added to the eel feed, or added to the feed. Soy isoflavones or genistein are pre-added at the manufacturing stage.

A well-known thing can be used for genistein, and it is not specifically limited. For example, a finished product can be used, a soy isoflavone containing genistein can be used as it is, a soy isoflavone can be extracted, purified, treated, separated or highly purified by a known method, or a soy isoflavone can be used The processed product may be obtained by separation, extraction, fermentation, or the like by known methods, or may be synthesized by known methods. For example, when the above-mentioned soybean isoflavone contains 10% by weight or more of genistein, the advantages are that it is easy to obtain, manufacture, and prepare, and it is possible to induce feminization of eels with certainty and high efficiency. The advantages of high-quality edible cultured eel with a high ratio of medium adipose tissue and mass production.

In addition, as long as the feminization-inducing effect on eels is maintained, the genistein of the present invention may include pharmacologically acceptable salts thereof, and genistein derivatives.

The feed for eel only needs to contain at least soy isoflavones (or soy isoflavone aglycone, or one or more of these specific compounds, such as genistein), and may also contain other blending, composition, etc. .

For example, in the feed for eel, the blending and composition of ingredients other than soy isoflavone (or soy isoflavone aglycone, or one or more of the specific compounds) can be the same as those of the commonly used mixed feed. The mixed feed is a mixture of nutrients suitable for eel growth at an appropriate ratio, and may contain, for example, 50% by weight or more of fish meal in a dry matter ratio, and may further contain starch, calcium phosphate, salt, yeast, herbal extracts, and the like.

The fish meal in the mixed feed can be a known one, and it is not particularly limited, and for example, it can be a powder obtained by processing sardines, mackerel, herring, trevally, and the like. Moreover, it may be the fish meal of another fish, and the fish meal of a plurality of fish species may be mixed. It can be appropriately selected in consideration of the type of eel, growth state, cost, and the like.

In addition, for example, lactic acid bacteria, Clostridium butyricum, digestive enzymes, dried vegetables, and the like can be appropriately contained, for example, components that improve the growth efficiency of eel.

＜Feminization-inducing agent for eel＞ In the production of the edible cultured eel (or a group thereof) of the present invention, the eel-inducing feminization agent can be, for example, one containing soy isoflavones at a daily intake of 10 mg/kg or more (eel body weight, the same below) as an active ingredient, and a daily intake of 10 mg/kg or more (eel body weight, the same below) as an active ingredient. Those containing soy isoflavone aglycone with a daily intake of 10 mg/kg or more as an active ingredient, and those containing genistein with a daily intake of 1.2 mg/kg or more as an active ingredient.

The eel-inducing feminization agent contains soy isoflavones (or soy isoflavone aglycones, or one or two or more specific compounds thereof, such as genistein) as active ingredients, and is used to make eels in juveniles and/or young eels. By ingesting soy isoflavones and the like, eel feminization can be induced reliably and efficiently, and high-quality edible cultured eels with a medium-sized or larger size and a high adipose tissue ratio in skeletal muscle can be produced and mass-produced.

In the case of mixed feed, the approximate amount of bait given is generally 5~8% of the body weight from the period from the young eel to the small eel (for example, about 0.2g ~ 20g), and it grows in the period of the small eel (for example, about 20g ~ 30g). 2~3% of body weight. When the feeding amount is 2% of the body weight, the daily intake of soybean isoflavones is preferably 10 mg/kg or more, more preferably 40 mg/kg or more, and most preferably 200 mg/kg or more. In addition, from the viewpoint of feed efficiency, the daily intake of soybean isoflavones is preferably 16 g/kg or less, more preferably 6.4 g/kg or less, and most preferably 3.2 g, when the feeding amount is 8% of the body weight. /kg or less.

For example, according to the growth degree of the eel, the daily intake of soy isoflavones can be 25mg/kg~16g/kg (eel body weight) from juvenile eel to small eel (for example, the body weight is about 0.2g or more to less than about 20g), preferably 100mg/kg~6.4g/kg, the optimal intake is 500mg/kg~3.2g/kg, and the daily intake of soy isoflavones is 10mg/kg~16g/kg ( eel body weight), more preferably 40 mg/kg~6.4g/kg, and optimally 200 mg/kg~3.2g/kg.

In other respects, in the eel-inducing feminizing agent, in terms of the amount of bait being 2% of the body weight, it is preferable that the daily intake of soybean isoflavone aglycone is more than 10 mg/kg, more preferably more than 40 mg/kg, and the most Preferably, it is more than 200 mg/kg. In addition, from the viewpoint of feed efficiency, the daily intake of soybean isoflavone aglycone is preferably 16 g/kg or less, more preferably 6.4 g/kg or less, when the feeding amount is 8% of the body weight. Preferably, it is 3.2 g/kg or less.

For example, according to the growth degree of the eel, the daily intake of soybean isoflavone aglycone 25mg/kg~16g/kg (eel body weight) from the young eel to the young eel (for example, the body weight is about 0.2g or more to less than about 20g), and more The optimal intake is 100 mg/kg ~ 12 g/kg, the best intake is 500 mg/kg ~ 8 g/kg, and the daily intake of soybean isoflavone aglycone 10 mg/kg during the period of small eels (such as about 20 g or more to about 30 g in weight) ~16g/kg (eel body weight), more preferably 40mg/kg~6.4g/kg, and optimally 200mg/kg~3.2g/kg.

On the other hand, in the eel-inducing feminization agent, in terms of the amount of bait being 2% of the body weight, the daily intake of genistein is preferably 1.2 mg/kg or more, more preferably 4.0 mg/kg or more, The best is above 20mg/kg. Furthermore, from the viewpoint of feed efficiency, the daily genistein intake is preferably 4.0 g/kg or less, more preferably 1.6 g/kg or less, and most preferably 8% of the body weight. Below 0.8g/kg.

For example, according to the growth degree of the eel, the daily intake of genistein is 3mg/kg~4.0g/kg (eel body weight) from juvenile eel to small eel (for example, the body weight is about 0.2g or more to less than about 20g), preferably In order to ingest 10mg/kg~1.6g/kg, preferably 50mg/kg~800mg/kg, daily intake of genistein 1.2mg/kg~1.5 in the period of small eels (for example, about 20g or more to about 30g body weight) g/kg (eel body weight), more preferably 4 mg to 600 mg/kg, and more preferably 20 mg/kg to 300 mg/kg.

Excipients, lubricating agents, binding agents, disintegrating agents, solvents, dissolving aids, suspending agents, buffering agents, tonicity agents, and preservatives can be appropriately added to the eel feminizing agent according to the purpose, use, dosage form, etc. agent, antioxidant, pH adjuster, dispersant, colorant, defoamer, etc.

Preferred examples of excipients include lactose, white sugar, D-mannitol, starch, crystalline cellulose, light silicic anhydride and the like.

Preferred examples of the lubricating agent include magnesium stearate, calcium stearate, talc, colloidal silica, and the like.

Preferred examples of the binding agent include crystalline cellulose, white sugar, D-mannitol, dextrin, hydroxypropylcellulose, hydroxypropylmethylcellulose, polyvinylpyrrolidone, and the like.

Preferred examples of disintegrating agents include starch, carboxymethyl cellulose, calcium carboxymethyl cellulose, croscarmellose sodium, sodium carboxymethyl starch, and the like.

Preferred examples of the solvent include water for injection, alcohol, propylene glycol, polyethylene glycol, sesame oil, corn oil, and the like.

Preferable examples of dissolution aids include polyethylene glycol, propylene glycol, D-mannitol, benzyl benzoate, ethanol, triaminomethane, cholesterol, triethanolamine, sodium carbonate, sodium citrate, and the like.

Preferred examples of the suspending agent include surfactants (stearyl triethanolamine, sodium lauryl sulfate, lauryl aminopropionic acid, lecithin, benzalkonium chloride, benzonine chloride, monostearate) acid glycerides, etc.), hydrophilic polymers (polyvinyl alcohol, polyvinylpyrrolidone, sodium carboxymethyl cellulose, methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and many more.

Preferable examples of the buffering agent include buffers such as phosphate, acetate, carbonate, citrate, tartrate, tris, and HEPES.

Preferred examples of tonicity agents include sodium chloride, glycerin, D-mannitol, and the like.

Preferable examples of the agent for the purpose of preservation include, for example, sodium mercuric thiosalate, benzoic acid esters, phenoxyethanol, chlorobutanol, benzyl alcohol, phenethyl alcohol, dehydroacetic acid, sorbic acid, and Various other preservatives, antibiotics, synthetic antimicrobials, etc.

Preferable examples of antioxidants include, for example, sulfites, ascorbic acid, and the like.

Preferred examples of pH adjusters include acids such as hydrochloric acid, carbonic acid, acetic acid, citric acid, phosphoric acid, boric acid, and sulfuric acid, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, and carbonic acid. Alkali metal carbonate or bicarbonate such as sodium, alkali metal acetate such as sodium acetate, alkali metal citrate such as sodium citrate, alkali such as trimethylolamine, monoethanolamine, diisopropanolamine, and the like.

Preferable examples of the dispersing agent include sodium carboxymethyl cellulose, hydroxypropyl methyl cellulose, polyvinylpyrrolidone, polysorbate 80, and the like.

Preferable examples of colorants include caramel coloring, gardenia coloring, anthocyanin coloring, nopaline coloring, capsaicin coloring, safflower coloring, red yeast rice coloring, carotene coloring, carotenoid coloring, flavonoid coloring, Cochineal, Amaranth (Red No. 2), Erythrosine (Red No. 3), Allura Red AC (Red No. 40), New Carmine (Red No. 102), Rose Bengal (Red No. 104), Rose Bengal Red (Red No. 105), Acid Red (Red No. 106), Tartrazine Yellow (Yellow No. 4), Sunset Yellow FCF (Yellow No. 5), Fast Green FCF (Green No. 3), Bright Blue FCF (Blue No. 1) ), indigo carmine (blue No. 2), copper chlorophyll, sodium copper chlorophyll, etc.

Preferred examples of the defoaming agent include silicone, simethicone, polysiloxane emulsion, sorbitan sesquioleate, nonionic substances, and the like.

In addition, supplementary ingredients such as light-absorbing pigments (riboflavin, adenine, adenosine, etc.) for preservation/efficiency aids, chelating agents for stabilization, reducing agents (vitamin C, Citric acid, etc.), carbohydrates (sorbitol, lactose, mannitol, starch, sucrose, glucose, polydextrose, etc.), casein digest, various vitamins, lactic acid bacteria, Clostridium butyricum, digestive enzymes, dried vegetables, etc.

(Example) (Example 1) In Example 1, it was examined whether soy isoflavones could induce eel feminization.

70 young eels of indeterminate sex (average body weight 0.4 g) were put into a 150L FRP water tank, and the mixed feed containing soybean isoflavones in various proportions was fed and fed. The water temperature was set at 28°C and raised.

The feeding frequency of the mixed feed supplemented with soybean isoflavones was 5 times a week. The amount of each feeding is 7-8% of the body weight in the first two months, and then about 2.5% of the body weight.

About 6 months after the start of rearing, a small eel with a body weight of about 30 g or more was appropriately sampled, and male and female were identified.

Male and female discrimination was carried out by morphological observation of the gonads. Those with ovaries were considered females, and those with testicles were considered males.

The results are shown in Tables 1 and 2. In each table, "number of strips" indicates the number of individuals sampled, and "soy isoflavone addition ratio" indicates the amount of soybean isoflavones added when the weight of the mixed feed before the addition of soybean isoflavones and before use is 100%. (% by weight), "aglycone content ratio" means the content of soybean isoflavone aglycone by weight (% by weight) when the weight of the mixed feed before the addition of soybean isoflavones and before use is 100% (weight %), "genistein" Flavonoid content ratio" means the genistein content weight ratio (% by weight) when the weight of the mixed feed before soy isoflavone addition and use before preparation is 100%, and the "female fish ratio" means the proportion of females in the number of sampled individuals. Proportion. In addition, "the weight of soybean isoflavone aglycone content" means the weight of the non-sugar part in the added soybean isoflavone, and the analytical value obtained by the well-known test method was used. In addition, "control" is the result of feeding and rearing the normal mixed feed without adding soy isoflavones.

As shown in Table 1, 1 wt % or more of soybean isoflavones were added to the eel feed from the juveniles to the young eels, and the eels were raised to induce feminization of the eels. In addition, as shown in Table 2, when the eel feed was raised with the aglycone content ratio of 0 to 0.040 wt % relative to the feed weight, all individuals differentiated into males, and the aglycone content ratio was 0.100 wt %. % or more, 46% of individuals were induced to feminize, when 0.336% by weight, 95% of individuals were induced to feminize, and when 1.076% by weight or more, all individuals were induced to feminize. From another point of view, if attention is paid to the genistein contained in the feed by adding soybean isoflavones, the feed for eels with the genistein content ratio of 0 to 0.004% by weight is raised in the period from juvenile to young eel. In contrast, when the genistein content was 0.01% by weight, 46% of the individuals were induced to feminize, and when the content of genistein was 0.031% by weight, 95% of the individuals were induced to feminize. When the content ratio is 0.155% by weight or more, all individuals are induced to feminize.

In this experiment, each feeding amount was 7-8% of body weight in the first two months, and then about 2.5% of body weight. Based on this conversion, when the addition ratio of soybean isoflavones was 1% by weight, each time in the first two months The intake of soy isoflavones is about 700~800mg/kg body weight, and the intake of soy isoflavones each time is about 250mg/kg body weight. Similarly, when the content of aglycone relative to the weight of the feed is 0.100% by weight, the intake of aglycone is about 70.0-80.0 mg/kg body weight each time for the first two months, and the intake of aglycone each time after that is about 70.0~80.0 mg/kg When the aglycone content is 0.336% by weight relative to the weight of the feed, the aglycone intake is about 235.2~268.8mg/kg body weight each time in the first two months, and then every time The aglycone intake for one time is about 84.0mg/kg body weight, and when the aglycone content relative to the weight of the feed is 1.076% by weight, the aglycone intake per time for the first two months is about 753.2~860.8mg/ kg body weight, and each subsequent aglycone intake was about 269.0 mg/kg body weight. In addition, when the genistein content is 0.01% by weight, the genistein intake is about 7-8 mg/kg body weight each time for the first two months, and the genistein intake is about 2.5 mg/kg for each subsequent time. mg/kg body weight, when the content of genistein is 0.031% by weight, the intake of genistein is about 21.70 ~ 24.8 mg/kg body weight each time in the first two months, and the intake of genistein each time after that The amount of genistein is about 7.75mg/kg body weight, when the genistein content is 0.155% by weight, the genistein intake per time for the first two months is about 108.5~1,240 mg/kg body weight, and the gold The intake of genistein is approximately 38.75 mg/kg body weight.

(Example 2) In Example 2, males and females were compared based on the analysis of the total length, body weight, and nutritional components of eels.

The total length and body weight were measured for eels not feminized with soy isoflavones (male eels, n=7) and eels feminized with soy isoflavones (females, n=5). In addition, the BMI value is calculated by the above-mentioned formula (A) for each individual.

Then, the skeletal muscles of the back and abdomen were harvested for nutritional analysis, the protein and lipid contents were determined, and the lipid/protein ratio in the skeletal muscles of the back and abdomen was calculated.

Figure 1 is a graph comparing body weight and lipid/protein ratio between males and females. In the figure, the horizontal axis represents body weight (g), and the vertical axis represents the lipid/protein ratio.

As shown in Fig. 1, when the eel body weight is X (g) and the lipid/protein ratio is Z, the cultured eel can clearly identify male and female with the following formula (I") as a boundary. Z=-0.001X+1.95 (I”) .

FIG. 2 is a graph comparing BMI values and lipid/protein ratios between males and females. In the figure, the horizontal axis represents the BMI value, and the vertical axis represents the lipid/protein ratio.

As shown in Figure 2, when the BMI value is Y and the lipid/protein ratio is Z, the cultured eel can clearly identify male and female with the following formula (II") as the boundary. Z=-Y+2.45 (II”)

(Example 3) In Example 3, the gonad weight index (GSI; gonad weight/body weight) of eels feminized with soybean isoflavones was calculated, and the relationship between the gonad weight index and the fish meat firmness after conditioning was evaluated.

First, the eels that were not feminized with soybean isoflavones (male eel, n=12, body weight 200-350 g) and the eels that were induced to feminize with soybean isoflavones (female eel, n=15, body weight 200-530 g) were treated respectively. ) for body weight measurement, genitals were removed and their weights were determined. The gonad weight per unit body weight (unit: %) was then calculated as the gonad weight index.

As a result, the gonad weight per unit body weight of male eels was less than 0.35%, whereas the gonad weight per unit body weight of female eels induced by soybean isoflavones exceeded 0.35%.

Next, a slit was cut along the center of the ventral side of each eel, and the eel was grilled on one side by heat processing at 850°C for 600 seconds on the skin side and 600 seconds on the meat side using an electric grill pan 3H-210 (manufactured by HIGOGRILLER). After peeling, take out the fish fillets with a width of about 1cm from 3 places on the ventral part, and make 1 individual into 3 samples. The average value is the fish meat hardness index.

Fig. 3 is a graph showing the relationship between the gonad weight index and the rupture load of the fish on the ventral side after heat conditioning. In Fig. 3, the horizontal axis represents the gonad weight index (GSI; gonad weight per unit body weight. Unit: %) of eel, and the vertical axis represents the rupture load of the ventral fish after heating conditioning (unit: N).

As shown in Figure 3, when the gonad weight index is a (%) and the breaking load of the fish on the ventral side after heating conditioning is b (N), the cultured eel can clearly identify male and female with the following formula (III") as the boundary. b=2a+1 (III”)

FIG. 1 is a graph comparing the body weight and the lipid/protein ratio between males and females in Example 2. FIG. FIG. 2 is a graph comparing the BMI value and the lipid/protein ratio between males and females in Example 2. FIG. FIG. 3 is a graph showing the relationship between the gonad weight index and the rupture load of the fish on the ventral side after heat conditioning in Example 3. FIG.

Claims (6)

A kind of edible culture eel, when taking eel body weight as X (g), lipid/protein ratio is Z, satisfy following formula (I); Z>-0.001X+1.95 (250<X<1,800) (I). An edible cultured eel whose body weight exceeds 250g, and the value of the following formula (A) is BMI, and when the BMI value is Y and the lipid/protein ratio is Z, the following formula (II) is satisfied; BMI=body weight (g) /{full length (mm)} ² (A) ; Z>-Y+2.45 (0.2<Y<2.0) (II) . An edible cultured eel whose body weight exceeds 250 g, and when the gonad weight per unit body weight is a (%), and the breaking load of the fish meat during thermal processing for 10 minutes is b (N), the following formula (III) is satisfied; b<2a+1 (0.1<a<4) (III). The edible cultured eel according to any one of Claims 1 to 3, wherein the adipose tissue in the skeletal muscle of the back or abdomen is locally present in the form of a mesh. The edible cultured eel according to any one of claims 1 to 4 is a feed for eel that contains 0.05% by weight or more of soybean isoflavones in a dry matter ratio during the period of juvenile and/or young eel. An edible cultured eel group is formed by more than 10 eels, and contains the edible cultured eel individuals as described in any one of claim 1 to 5 in a ratio of 12% or more.

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